Method of, and apparatus for standardizing slivers

ABSTRACT

A method and apparatus for standardizing slivers during their formation in a textile machine such as a carding machine including a first regulating unit at the input of the machine for correcting long-term fluctuations in the supply of material and a second regulating unit inside the machine for correcting shortterm fluctuations by altering the draft of the sliver, and wherein, in order to keep the sliver deposition unit at a constant level, the difference between the variable rate of the second regulating unit and the rate of travel of the sliver is adjusted by use of a sliver reservoir, the filling level of which is monitored and controlled so that it falls at all times within a predetermined range.

[ METHOD OF, AND APPARATUS FOR STANDARDIZING SLIVERS [75] Inventor: Peter Feller, Uster, Switzerland [73] .Assignee: Zellweger, Inc., Uster, Switzerland [22] Filed: Sept. 7, 1972 211 App]. No.: 286,865

30 Foreign Application Priority Data Sept. 7, 1971 Switzerland 13143/71 [52] US. Cl. 19/240 1 [51] Int. Cl...., D01h 5/38 [58] Field of Search 19/239, 240, 241

[56] References Cited UNITED STATES PATENTS 3,403,426 10/1968 Stiepel et al. l9/240 3,703,023 I 1/1972 ,Krauss et al. l9/240 FOREIGN PATENTS OR APPLICATIONS Great Britain 19/240 Dec. 10, 1974 Primary Examiner-Dorsey Newton Attorney, Agent, or Firm-Craig & Antonelli 57 I ABSTRACT A method and apparatus for standardizing slivers during their formation in a textile machine such as a carding machine including a first regulating unit at the input of the machine for correcting long'term fluctuations in the supply of material and a second regulating unit inside the machine for correcting short-term fluctuations by altering the draft of the sliver, and wherein, in order to keep the sliver deposition unit at a constant level, the difference between the variable rate of the second regulating unit and the rate of travel of the sliver is adjusted by use of a sliver reservoir, the filling level of which is monitored and controlled so that it falls at all times within a predetermined range.

10 Claims, 3 Drawing Figures mamm mmm 3.852.848 sum 1 or w p m WW"?! I HHHI Fig.1

PATENTED E I 01974 3, 852.848

sum 2 us 3 PATENTEU DEC 1 01974 sum 3 or 5 This invention relates to a method of, and an-apparatus for, standardizing slivers by suitably regulating their thickness or their weight per unit length during their formation in a textile machine, more particularly a carding machine.

There are already methods and apparatus for standardizing slivers which function on one of several known principles. In one known system, the quantity of fiber material delivered to the textile machine is measured and the signal generated by measurementis used to directly regulate the quantity of fiber. However, regulating systems functioning on this principle involve the use of a complicated and expensive measuring element, and considerable difficulties are involved in achieving the requisite long-term stability and adequate independence of the properties of the fiber material. In addition, it is not possible with systems of this kind to correct' brief fluctuations and irregularities which can be caused by the textile machine itself.

In a second known system, the thickness of the sliver produced is measured and the measured value is used to control the quantity of fiber delivered.

Although regulating systems functioning on the basis of the principle involved in this system make it possible, for simple measuring elements to be used, it is only possible with regulating systems of this kind to correct extremely long-term inconsistencies.

In a third known system, the thickness of the sliver produced is measured and the measured value regulates the output rate of the sliver delivered in such a way that it is standardized. In a fourth known system, a regulating arrangement, gener ally in the form of a drawing arrangement, is situated at the output end of the textile machine. A measuring element preceding this regulating arrangement measures the thickness of the sliver and controls the draft of the drawing arrangement in such a way that the thickness of the sliver is standardized at the output end.

Regulating systems functioningon the basis of the principle embodied in the third system enable short fluctuations to be regularized while those functioningon the basis of the principle embodied in the forth system enable even extremely short fluctuations (a few centimeters in length) to be regularized. Unfortunately, the basic disadvantage of these two systems is the variable output rate of the sliver delivered. This calls for a high-performance regulating unit because the sliverdeposition unit (the so called can stock) also has to be driven at this variable rotational speed. Since production also fluctuates with the variable output rate, the capacity of the textile machine cannot be fully utilized, in other words, its efficiency diminishes.

The present invention provides a method for standardizing the cross section or weight per unit length of the sliver produced by a textile machine, comprising a first regulating unit at the inlet end of the machine for correcting long-term fluctuations in the supply of material and a second regulating unit inside the machine for correcting short-term fluctuations by altering the draft, wherein, in order to keep the speed of a sliverdeposition unit at a constant level, the difference between the variable input or output rate of the second regulating unit and therate of travel of the sliver is corrected in the following-sectionof the machine through the interposition of sliver reservoir, and the speed differential and/or the filling level of the sliver reservoir, is monitored and, as a result of such monitoring, one or both of the regulating units are influenced in such a way that the average filling level of the sliver reservoir remains constant.

The invention also provides an apparatus for standardizing the cross section or weight per unit length of the sliver produced by a textile machine comprising a first regulating unit for correcting long-term fluctuations in the supply of material arranged at the inlet end of the machine and a second regulating unit for correcting short-term fluctuations arranged inside the machine, the said apparatus comprising a sliver reservoir at the side of the second regulating unit, means for monitoring the fillin'g level of the sliver reservoir and for obtaining a signal from such monitoring, and means responsive to the signal for influencing one or both regulating units in such a way that the filling level of the reservoir does not exceed predetermined limits.

Exemplary embodiments of the invention will now be described by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of a regulating system in a carding machine with a sliver reservoir following the regulating unit at the output end;

FIG. 2 is a schematic diagram ofa regulating system in a carding machine with a sliver reservoir preceding the regulating units at the output end; and

FIG. 3 is a detailed schematic view of a sliver reservoir.

FIG. I diagrammatically illustrates a carding macontrolled chine consisting of a cylinder 1 which is preceded by a I for example,

licker-in 2 and a feed roller 3. A film of fiber is removed by way of a doffer 4 and a doffing comb 5. Instead of the otherwise usual calender rollers, a drawing arrangement 7 is provided at the output of the carding machine having a rear cylinder 8 which is driven at a constant rotational speed and a front cylinder 9 which is driven at a'variable rotational speed controlled by elements known per se,'which form a regulating means for the sliver. An element 6, such as a conventional measuring nozzle, such as described in U.S. Pat. No. 3,435,673, for measuring the thickness of the sliver, provides an output signal to a regulator 12 which pro duces a variable drive signal directed to a variable drive unit-10. The measuring element 6 can be arranged in front of, inside or behind the drawing arrangement 7.

A measurement-induced drive signal, or a manipulated variable, from the regulator 12 controls the rotational speed of the feed roller 3 through an input regulating means, formed by a controller 13 provided with an integrating component which detects the-average deviation and a variable drive 17, in the sense. that, if the output rate of the sliver 14 is too high, the quality of material delivered is reduced andvice-versa. Through the reduction in the quantity of material supplied, a thinner film of fiber is formed at the output end of the carding machine, with the result that the drawing arrangement is switched to a lower draft, i.e., to a lower output per unit of time.

In order to correct differences in speed occurring briefly between the front cylinder 9and a can stock 16, there is provided a sliver reservoir ll known per se, the filling level of which is monitored at least at one point, by means of a. photocell 15. The filling level of the reservoir 11 can also be continuously measured by other suitable means.

The signal obtained from the photocell l5 acts upon the variable drive 10, or is applied to the variable drive 17 by way of a summing junction 25 also connected to controller 13, in the sense that the filling of the sliver reservoir 11 remains within predetermined limits. This can be achieved, for example, by adjusting the relative speeds by a few percent between the front cylinder 9 and the coiling mechanism 16, in such a way that the sliver reservoir 11 is slowly emptied. When the filling level falls below a desired minimum, the photocell l5 responds and increases the rotational speed of the feed roller 3 so that the reservoir is filled again.

The embodiment shown in FIG. 2 differs from that shown in FIG. 1 in that the front cylinder 9 of the drawing arrangement is driven at a constant rotational speed while the rear cylinder 8 is driven at a variable rotational speed. In thiscase, the sliver reservoir 11 is arranged between the' drawing arrangement 8, 9 and the calender rollers 18.

It is also possible to control the delivery of the sliver to the can stock 16 by other means than the sliver reservoir 11. FIG. 3 shows an arrangement suitable for this purpose. The deviation fromthe average draft between the drawingcylinders 8 and 9 is integrated by means of a standard differential gear mechanism 19 and adjusts a rocker arm 20 on which rollers 21 and 23 are rotatably mounted. The shaft 24 for one of the cylinders 8 is connected to a bevel gear25 which meshes with bevel gear 26, connected to gear 27 in the differential mechanism 19. The differential gears 28 and 29 mesh with gears 27 and 30, the gear 30 being connected to the bevel gear. 31, which is driven by the shaft 32 for one of the cylinders 9 by way of gears 33, 34 and 35. An output gear 36 is connected to the spider 37 of the differential gear mechanism so that differences in speed between the cylinders 8 and 9 produce rotation of the spider 37, which rotation is transferred via gears 36 and 38 through the bevel gears 39 and 40' to the rocker arm 20.

The sliver is guided over the roller 2l, over a fixed roller 22 and over the roller 23 to the can stock 16. The direction of rotation of the rocker arm 20'is selected in such a way that it moves downwards as long as the drawing arrangement 8, 9 is producing more sliver than the can stock 16 is receiving. The sliver delivered in excess is picked up by the increasing length between the rollers. Accordingly, the positionof the arm 20 can be directly used to control the regulated drive 17.

While I have shown and-described several embodiments in accordance with. the present invention, it is understood that the same is not limited thereto, but is susceptible of numerous changes and modifications as known to those skilled in the art, and I therefore do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

What I'claim is:

l. A method for standardizing the cross section or weight per unit length of a sliver produced by a textile machine, comprising the steps of measuring the supply of material at the outlet of the machine, drafting the material subsequent to the measuring thereof, correctsupply of material at the outlet of the machine, correcting short-term fluctuations in the material at the outlet of the machine in response to the measured supply of material by altering the draft thereof, supplying the sliver at the outlet of the machine to a coiling mechanism, and, in order to keep thespeed of the coiling mechanism at a constant level, adjusting the difference between the variable rate of the short-term correction operation and the rate of travel of the sliver by supplying said sliver to a sliver reservoir prior to delivery to said coiling mechanism, monitoring the filling level of the sliver reservoir and, as a result of such monitoring, controlling at least one of said correcting operations in I such a way that the average filling level of the sliver resing long-term fluctuations in the supply of material at I the inlet of the machine in response to the measured ervoir remains constant.

2. A method as claimed in claim 1, wherein the sliver reservoir whose filling level is to be controlled, is monitored and arranged at the output of a carding machine.

3. An apparatus for standardizing the cross section or weight per unit length of the sliver produced by a textile machine which includes a feed roller, a main cylinder and a doffer, said apparatus comprising measuring means for measuring the cross section of the sliver at the output of said textile machine, first regulating means responsive to said measuring means for controlling the speed of the feed roller of said textile machine to correct long-term fluctuations in the supply of material received at the inlet end of the textile machine and second regulating means in the form of a drawing arrangement including a rear pair of cylinders connected to said textilemachine to be driven therewith, a front pair of cylinders, and drive means responsive to said measuring means for driving said front pair of cylinders at a variable rate to correct short-term fluctuations in the material received at the outlet of said textile machine, a sliver reservoir receiving the sliver obtained from said second regulating means, detection means for generating a signal representative of the filling level of said sliver reservoir, control means responsive to the signal from said detection means for influencing at least one of said first and second regulating means in such a way that the filling level of the reservoir is maintained within a predetermined range, and a coiling mechanism receiving the sliver from said sliver reservoir and being connected to the doffer of said textile machine to be driven at the same speed therewith.

4. An apparatus as'claimed in claim 3, where said sliver reservoir is disposed at the output of said drawing arrangement.

5. An apparatus as claimed in claim 3, further including a pair of calender rollers positioned at the output of said textile machine, and wherein said sliver reservoir is arranged between the drawing arrangement and said pair of calender rollers. 1

6. An apparatus as claimed in claim 3, further includ ing a differential gear mechanism for integrating the difference in speed between said front and rear pairs of cylinders to control the speed of the sliver between the coiling mechanism and said front pair of cylinders of the drawing arrangement, and wherein means are provided for controlling the filling level of the sliver reservoir and the rotational speed of said feed roller of the textile machine in response to the integral value ob-. tained from said differential mechanism.

7. An apparatus as claimed in claim 3, wherein said second regulating means includes means for adjusting the speed of delivery of the sliver by a few percent between said measuring means and said coiling mechanism. i

8. An apparatus as claimed in claim 3, wherein said detection means is a photocell for monitoring the filling level of said sliver reservoir.

9. An apparatus for standardizing the cross section or weight per unit length of the sliver produced by a textile machine which includes a feed roller, a main cylinder and a doffer, said apparatus comprising measuring means for measuring the cross section of the sliver at the output of said textile machine, first regulating means responsive to said measuring means for controlling the speed of the feed roller of said textile machine to correct long-term fluctuations in the supply of material received at the inlet end of the textile machine and second regulating means in the form of a drawing arrangement including a rear pair of cylinders connected to said textile machine to be driven therewith, a front pair of cylinders, and drive means responsive to said measuring means for driving said front pair of cylinders at a variable rate to' correct short-term fluctuations in the material received at the outlet of said textile machine, a sliverreservoir receiving the sliver obtained from 'said second regulating means, a coiling mechanism receiving the sliver from said sliver reservoir and being connected to the doffer of said textile machine to be driven at the same speed therewith, a differential gear mechanism for integrating the difference in speed between said front and rear pairs of cylinders to control the speed of the sliver between the coiling mechanism and said front pair of cylinders of the drawing arrangement, means for controlling the length of sliver in said sliver reservoir and the rotational speed of said feed roller of the textile machine in response to the integral value obtained from said differential mechanism, and a'pivotable rocker arm connected to said differential gear arrangement and carrying at least one roller around which said sliver passes so as to adjust the position of said rocker arm in accordance with the difference in speed between said front and rear pairs of cylinders.

10. An apparatus as claimed in claim 9, wherein said differential gear arrangement is driven by the-respective front and rear pairs of cylinders of said drawing arrangement. 

1. A method for standardizing the cross section or weight per unit length of a sliver produced by a textile machine, comprising the steps of measuring the supply of material at the outlet of the machine, drafting the material subsequent to the measuring thereof, correcting long-term fluctuations in the supply of material at the inlet of the machine in response to the measured supply of material at the outlet of the machine, correcting short-term fluctuations in the material at the outlet of the machine in response to the measured supply of material by altering the draft thereof, supplying the sliver at the outlet of the machine to a coiling mechanism, and, in order to keep the speed of the coiling mechanism at a constant level, adjusting the difference between the variable rate of the short-term correction operation and the rate of travel of the sliver by supplying said sliver to a sliveR reservoir prior to delivery to said coiling mechanism, monitoring the filling level of the sliver reservoir and, as a result of such monitoring, controlling at least one of said correcting operations in such a way that the average filling level of the sliver reservoir remains constant.
 2. A method as claimed in claim 1, wherein the sliver reservoir whose filling level is to be controlled, is monitored and arranged at the output of a carding machine.
 3. An apparatus for standardizing the cross section or weight per unit length of the sliver produced by a textile machine which includes a feed roller, a main cylinder and a doffer, said apparatus comprising measuring means for measuring the cross section of the sliver at the output of said textile machine, first regulating means responsive to said measuring means for controlling the speed of the feed roller of said textile machine to correct long-term fluctuations in the supply of material received at the inlet end of the textile machine and second regulating means in the form of a drawing arrangement including a rear pair of cylinders connected to said textile machine to be driven therewith, a front pair of cylinders, and drive means responsive to said measuring means for driving said front pair of cylinders at a variable rate to correct short-term fluctuations in the material received at the outlet of said textile machine, a sliver reservoir receiving the sliver obtained from said second regulating means, detection means for generating a signal representative of the filling level of said sliver reservoir, control means responsive to the signal from said detection means for influencing at least one of said first and second regulating means in such a way that the filling level of the reservoir is maintained within a predetermined range, and a coiling mechanism receiving the sliver from said sliver reservoir and being connected to the doffer of said textile machine to be driven at the same speed therewith.
 4. An apparatus as claimed in claim 3, where said sliver reservoir is disposed at the output of said drawing arrangement.
 5. An apparatus as claimed in claim 3, further including a pair of calender rollers positioned at the output of said textile machine, and wherein said sliver reservoir is arranged between the drawing arrangement and said pair of calender rollers.
 6. An apparatus as claimed in claim 3, further including a differential gear mechanism for integrating the difference in speed between said front and rear pairs of cylinders to control the speed of the sliver between the coiling mechanism and said front pair of cylinders of the drawing arrangement, and wherein means are provided for controlling the filling level of the sliver reservoir and the rotational speed of said feed roller of the textile machine in response to the integral value obtained from said differential mechanism.
 7. An apparatus as claimed in claim 3, wherein said second regulating means includes means for adjusting the speed of delivery of the sliver by a few percent between said measuring means and said coiling mechanism.
 8. An apparatus as claimed in claim 3, wherein said detection means is a photocell for monitoring the filling level of said sliver reservoir.
 9. An apparatus for standardizing the cross section or weight per unit length of the sliver produced by a textile machine which includes a feed roller, a main cylinder and a doffer, said apparatus comprising measuring means for measuring the cross section of the sliver at the output of said textile machine, first regulating means responsive to said measuring means for controlling the speed of the feed roller of said textile machine to correct long-term fluctuations in the supply of material received at the inlet end of the textile machine and second regulating means in the form of a drawing arrangement including a rear pair of cylinders connected to said textile machine to be driven therewith, a front pair of cylinders, and drive means responsive to said measuring meanS for driving said front pair of cylinders at a variable rate to correct short-term fluctuations in the material received at the outlet of said textile machine, a sliver reservoir receiving the sliver obtained from said second regulating means, a coiling mechanism receiving the sliver from said sliver reservoir and being connected to the doffer of said textile machine to be driven at the same speed therewith, a differential gear mechanism for integrating the difference in speed between said front and rear pairs of cylinders to control the speed of the sliver between the coiling mechanism and said front pair of cylinders of the drawing arrangement, means for controlling the length of sliver in said sliver reservoir and the rotational speed of said feed roller of the textile machine in response to the integral value obtained from said differential mechanism, and a pivotable rocker arm connected to said differential gear arrangement and carrying at least one roller around which said sliver passes so as to adjust the position of said rocker arm in accordance with the difference in speed between said front and rear pairs of cylinders.
 10. An apparatus as claimed in claim 9, wherein said differential gear arrangement is driven by the respective front and rear pairs of cylinders of said drawing arrangement. 